Silane modified polyether waterproof coating and preparation method for improving hydrophobicity thereof

Abstract

The invention belongs to the technical field of waterproof materials, and particularly relates to a silane modified polyether waterproof coating and a preparation method for improving hydrophobicity of the silane modified polyether waterproof coating. The silane modified polyether waterproof coating is prepared from the following raw materials in parts by weight: 25 to 40 parts of polyether polyol, 40 to 50 parts of solid filler, 15 to 20 parts of plasticizer, 0.5 to 1.5 parts of silane end-capping reagent, 0.5 to 2 parts of silane coupling agent, 1 to 2 parts of water removal agent, 0.3 to 1 part of dispersing agent, 0.3 to 1 part of light stabilizer, 0.3 to 1 part of ultraviolet absorbent and 0.1 to 1 part of catalyst. The polyether polyol is obtained by random copolymerization of epoxypropane and epoxybutane, and the molecular weight of the polyether polyol is 8000-20000 g / mol. The silane modified polyether waterproof coating provided by the invention has good hydrophobicity and good mechanical strength, and meets the requirements on high-performance and environment-friendly waterproof coatings. The invention also provides a preparation method for improving the hydrophobicity of the polyether waterproof coating.

Description

Technical Field

[0001] The invention belongs to the technical field of waterproof materials, and particularly relates to a silane-modified polyether waterproof coating and a preparation method for improving the hydrophobicity of the coating. Background Art

[0002] With the rapid development of the construction industry, the demand for waterproof materials is growing. As an important part of waterproof projects, the performance and quality of waterproof coatings directly affect the safety and durability of construction projects. Traditional polyurethane waterproof coatings occupy an important position in the waterproof coating market due to their good mechanical properties, weather resistance and waterproof effect. However, polyurethane waterproof coatings release harmful substances such as isocyanates during the preparation and use process, posing a potential threat to the environment and human health, which limits their application in certain occasions with high environmental protection requirements.

[0003] In recent years, silane-modified polyether waterproof coatings, as a new type of environmentally friendly waterproof coatings, have received extensive attention and research due to their advantages such as being isocyanate-free, environmentally friendly, and curing without bubbles. Silane-modified polyether waterproof coatings use polyether polyols as the main raw material and are modified by introducing silane end-capping agents, which not only improves the weather resistance and water resistance of the coating, but also reduces the release of harmful substances, which is in line with the current development trend of green and environmental protection.

[0004] However, silane-modified polyether waterproof coatings still have some shortcomings in practical applications. Since their main chain structure is mainly difunctional polypropylene glycol (PPG), their hydrophobicity is much lower than that of silicone waterproof coatings. At the same time, due to the relatively low cross-linking density, the mechanical strength of silane-modified polyether waterproof coatings is also much lower than that of polyurethane waterproof coatings, which to a certain extent limits their application in some waterproof projects that require higher mechanical strength.

[0005] In order to improve the mechanical strength of silane-modified polyether waterproof coatings, researchers have tried a variety of methods, one of which is to extend the chain of low molecular weight PPG through isocyanate. This method can improve the mechanical strength of the coating to a certain extent, but it cannot change its lack of hydrophobicity. In addition, due to the presence of high-density urethane groups in the system, the overall viscosity of the coating is high and the construction performance is poor, and solvents need to be added for dilution, which not only increases production costs, but also loses the environmental advantages of silane-modified polyether.

[0006] Therefore, how to improve the hydrophobicity and mechanical strength of silane-modified polyether waterproof coatings and improve their construction performance while maintaining their environmental friendliness has become a problem that needs to be solved urgently. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a silane-modified polyether waterproof coating with good hydrophobicity and good mechanical strength to meet the market demand for high-performance, environmentally friendly waterproof coatings. The present invention also provides a preparation method for improving the hydrophobicity of the silane-modified polyether waterproof coating.

[0008] The silane-modified polyether waterproof coating of the present invention is prepared from the following raw materials in parts by weight: 25-40 parts of polyether polyol, 40-50 parts of solid filler, 15-20 parts of plasticizer, 0.5-1.5 parts of silane end-capping agent, 0.5-2 parts of silane coupling agent, 1-2 parts of water remover, 0.3-1 parts of dispersant, 0.3-1 parts of light stabilizer, 0.3-1 parts of ultraviolet absorber, and 0.1-1 parts of catalyst;

[0009] The polyether polyol is obtained by random copolymerization of propylene oxide and butylene oxide, and has a molecular weight of 8000-20000 g / mol, and a further preferred molecular weight of 12000-18000 g / mol. The polyether polyols are all self-produced by Shanghai Dongda Chemical Co., Ltd. through a bimetallic catalytic synthesis process. The specific preparation process is as follows: a measured amount of 2-functionality 2000 molecular weight or 3-functionality 3000 molecular weight polyether and DMC catalyst are added to a reactor, nitrogen is replaced twice, vacuumed and heated to 130°C, and the timing is 1 hour; PO is quickly added dropwise under negative pressure to initiate the reaction, and then BO and PO are added and the external circulation is started; after the addition is completed, the reaction is aged for 1 hour, unreacted monomers and small molecules are removed in vacuum, the temperature is reduced to 90°C, an antioxidant (1076) is added, and the mixture is stirred evenly to obtain a polyether with a target molecular weight and functionality.

[0010] The functionality of the polyether polyol is 2 or 3 or a mixture of functionality 2 and functionality 3.

[0011] The weight ratio of the functional group 2 to the functional group 3 is 1:1 to 3:1. The polyether polyol is the main chain structure of the silane-modified polyether waterproof coating. The difunctional polyether provides toughness and elongation, and the trifunctional polyether increases the crosslinking degree and provides mechanical strength.

[0012] The solid filler is one or more of silicon micropowder, talcum powder and heavy calcium carbonate. The addition of solid filler can improve the mechanical strength of silane-modified polyether and reduce the formulation cost.

[0013] The silane capping agent is an isocyanate silane capping agent, which is selected from one or more combinations of isocyanate propyl trimethoxy silane, isocyanate propyl dimethoxy silane and isocyanate propyl triethoxy silane.

[0014] The plasticizer is one of diisononyl phthalate (DINP), 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB), diisononyl cyclohexane 1,2-dicarboxylate (DINCH), and polypropylene glycol. The plasticizer plays a role in reducing viscosity and increasing film toughness in the system.

[0015] The dewatering agent is vinyl trimethoxy silane.

[0016] The silane coupling agent is one or two of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and N-(n-butyl)-3-aminopropyltrimethoxysilane.

[0017] The dispersant is a polymer-based dispersant, preferably BYK-180.

[0018] The light stabilizer is a hindered amine light stabilizer.

[0019] The ultraviolet absorber is a benzotriazole ultraviolet absorber.

[0020] The catalyst is a chelated tin catalyst.

[0021] The method for preparing the hydrophobicity of the silane-modified polyether waterproof coating comprises the following steps:

[0022] (1) Add polyether polyol, solid filler, plasticizer, dispersant, light stabilizer and ultraviolet absorber into a reaction bottle, stir evenly, heat to 100-110° C., evacuate to below -0.095 MPa, and dehydrate until the moisture content is controlled below 0.03%;

[0023] (2) When the moisture content is qualified, the temperature is lowered to below 60°C;

[0024] (3) adding a silane capping agent and reacting at 60-70° C. for 4-6 hours, and then cooling to below 40° C.;

[0025] (4) adding a silane coupling agent, a catalyst, and a water removing agent, stirring, and vacuum degassing to obtain a silane-modified polyether waterproof coating.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The preparation method of the silane-modified polyether waterproof coating of the present invention adopts a direct synthesis method, which greatly improves the production efficiency. The existing silane-modified polyether waterproof coatings all synthesize silane-modified polymers, i.e., MS resins, and then mix the MS resins and additives to produce waterproof coatings after dehydrating the base material. The entire production process from resin to finished coating product needs to go through the production process of two products, and the synthesis efficiency is low.

[0028] (2) The silane-modified polyether waterproof coating prepared by the method of the present invention introduces butylene oxide groups by modifying the main chain structure of the polyether polyol. Compared with propylene oxide, the flexible side chain of butylene oxide can play a hydrophobic and internal plasticizing role, reduce the viscosity of the polyether polyol and the waterproof coating product, and improve its hydrophobicity. When used as a waterproof material, it can significantly improve the waterproof effect of the coating.

[0029] (3) The method for preparing the hydrophobic silane-modified polyether waterproof coating of the present invention improves the cross-linking density of the system by designing the functionality of the polyether polyol molecules, thereby significantly improving the mechanical properties of the silane-modified polyether waterproof coating. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with specific embodiments.

[0031] Unless otherwise specified, the raw materials and additives used in the following examples and comparative examples are all commercially available products.

[0032] The method for preparing the hydrophobicity of the silane-modified polyether waterproof coating comprises the following steps:

[0033] (1) Add polyether polyol, solid filler, plasticizer, dispersant, light stabilizer and ultraviolet absorber into a reaction bottle, stir evenly and heat the materials to dehydrate them. The temperature is raised to 100-110° C., and a vacuum pump is turned on to continuously evacuate to below -0.095 MPa for dehydration. The moisture content of the mixture is controlled below 0.03%.

[0034] (2) After the moisture test is passed, the mixture is cooled to below 60°C.

[0035] (3) Add a silane capping agent to the reaction bottle and react at 60-70° C. for 4-6 hours. After the reaction is completed, cool the temperature to below 40° C.

[0036] (4) Add silane coupling agent, catalyst and dehydrating agent into the reaction bottle, stir for 30 minutes, and vacuum degas for 30 minutes before discharging the material to obtain a silane-modified polyether waterproof coating.

[0037] The polyether polyols a, b, c, and d prepared below are used in Examples 1-10 of the present invention.

[0038] Comparative Examples 1-3 used polyether polyols e and f prepared as follows.

[0039] a. The C2080B polyether polyol has a functionality of 2 and a molecular weight of 8000 g / mol.

[0040] b. The C2120B polyether polyol has a functionality of 2 and a molecular weight of 12000 g / mol.

[0041] c. The C2180B polyether polyol has a functionality of 2 and a molecular weight of 18000 g / mol.

[0042] d. The C3180B polyether polyol has a functionality of 3 and a molecular weight of 18000 g / mol.

[0043] e. The C2080 polyether polyol has a functionality of 2 and a molecular weight of 8000 g / mol.

[0044] f. The C2180 polyether polyol has a functionality of 2 and a molecular weight of 18000 g / mol.

[0045] The weight parts described below are all based on the same unit of mass.

[0046] Example 1

[0047] The silane-modified polyether waterproof coating is prepared from the following raw materials in parts by weight: 25 parts of polyether polyol C2080B, 50 parts of heavy calcium carbonate, 20 parts of DINP, 1 part of isocyanate propyltrimethoxysilane, 2 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 1.0 part of dewatering agent KH-171, 1 part of BYK-180, 0.3 parts of hindered amine light stabilizer UV-770, 0.3 parts of ultraviolet absorber UV-326, and 0.3 parts of catalyst T-12.

[0048] Example 2

[0049] The silane-modified polyether waterproof coating is prepared from the following raw materials in parts by weight: 25 parts of polyether polyol C2120B, 50 parts of heavy calcium carbonate, 20 parts of DINP, 0.8 parts of isocyanate propyltrimethoxysilane, 1.5 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 2 parts of dewatering agent KH-171, 1 part of BYK-180, 0.3 parts of hindered amine light stabilizer UV-770, 0.3 parts of ultraviolet absorber UV-326, and 0.1 parts of catalyst U-220H.

[0050] Example 3

[0051] The silane-modified polyether waterproof coating is prepared from the following raw materials in parts by weight: 25 parts of polyether polyol C2180B, 50 parts of heavy calcium carbonate, 20 parts of DINP, 0.5 parts of isocyanate propyltrimethoxysilane, 0.5 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 1.5 parts of dewatering agent KH-171, 1 part of BYK-180, 0.3 parts of hindered amine light stabilizer UV-770, 0.3 parts of ultraviolet absorber UV-326, and 0.1 parts of catalyst U-220H.

[0052] Example 4

[0053] The silane-modified polyether waterproof coating is prepared from the following raw materials in parts by weight: 25 parts of polyether polyol C3180B, 50 parts of heavy calcium carbonate, 20 parts of DINP, 1.2 parts of isocyanate propyltrimethoxysilane, 1.5 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 1.5 parts of dewatering agent KH-171, 1 part of BYK-180, 1 part of hindered amine light stabilizer UV-770, 1 part of ultraviolet absorber UV-326, and 1 part of catalyst T-12.

[0054] Example 5

[0055] The silane-modified polyether waterproof coating is prepared from the following raw materials in parts by weight: 25 parts of polyether polyol C2080B, 15 parts of C2180B, 30 parts of heavy calcium carbonate, 10 parts of silicon powder, 15 parts of DINP, 1.2 parts of isocyanate propyltrimethoxysilane, 1.5 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 1.5 parts of dewatering agent KH-171, 0.5 parts of BYK-180, 0.3 parts of hindered amine light stabilizer UV-770, 0.3 parts of ultraviolet absorber UV-326, and 0.3 parts of catalyst T-12.

[0056] Example 6

[0057] The silane-modified polyether waterproof coating is prepared from the following raw materials in parts by weight: 25 parts of polyether polyol C2120B, 15 parts of C3180B, 30 parts of heavy calcium carbonate, 10 parts of silicon powder, 15 parts of DINP, 1.5 parts of isocyanate propyltrimethoxysilane, 1.5 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 1.5 parts of dewatering agent KH-171, 0.5 parts of BYK-180, 0.3 parts of hindered amine light stabilizer UV-770, 0.3 parts of ultraviolet absorber UV-326, and 0.5 parts of catalyst T-12.

[0058] Example 7

[0059] The silane-modified polyether waterproof coating is prepared from the following raw materials in parts by weight: 20 parts of polyether polyol C2180B, 20 parts of C3180B, 30 parts of heavy calcium carbonate, 10 parts of silicon powder, 15 parts of DINP, 1.2 parts of isocyanate propyltrimethoxysilane, 1.5 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 1.5 parts of dewatering agent KH-171, 0.3 parts of BYK-180, 0.3 parts of hindered amine light stabilizer UV-770, 0.3 parts of ultraviolet absorber UV-326, and 1 part of catalyst T-12.

[0060] Example 8

[0061] The silane-modified polyether waterproof coating is prepared from the following raw materials in parts by weight: 25 parts of polyether polyol C2180B, 50 parts of heavy calcium carbonate, 20 parts of DINP, 1 part of isocyanate propyl dimethoxy silane, 1 part of N-(β-aminoethyl)-γ-aminopropyl trimethoxy silane, 0.5 part of N-(n-butyl)-3-aminopropyl trimethoxy silane, 1.5 parts of dewatering agent KH-171, 0.3 parts of BYK-180, 0.3 parts of hindered amine light stabilizer UV-7700, 0.3 parts of ultraviolet absorber UV-326, and 1 part of catalyst T-12.

[0062] Example 9

[0063] The silane-modified polyether waterproof coating is prepared from the following raw materials in parts by weight: 30 parts of polyether polyol C2180B, 10 parts of C3180B, 30 parts of heavy calcium carbonate, 10 parts of silicon powder, 15 parts of TXIB, 1.0 parts of isocyanate propyl trimethoxy silane, 0.2 parts of isocyanate propyl dimethoxy silane, 1.0 parts of N-(β-aminoethyl)-γ-aminopropyl trimethoxy silane, 1.0 parts of N-(n-butyl)-3-aminopropyl trimethoxy silane, 1.5 parts of dewatering agent KH-171, 0.3 parts of BYK-180, 0.3 parts of hindered amine light stabilizer UV-770, 0.3 parts of ultraviolet absorber UV-326, and 0.5 parts of catalyst U-220H.

[0064] Example 10

[0065] The silane-modified polyether waterproof coating is prepared from the following raw materials in parts by weight: 30 parts of polyether polyol C2180B, 10 parts of C3180B, 30 parts of heavy calcium carbonate, 10 parts of silicon powder, 15 parts of DINCH, 1.2 parts of isocyanate propyl triethoxysilane, 1.0 parts of N-(β-aminoethyl)-γ-aminopropyl trimethoxysilane, 1.0 parts of N-(n-butyl)-3-aminopropyl trimethoxysilane, 1.5 parts of dewatering agent KH-171, 0.3 parts of BYK-180, 0.3 parts of hindered amine light stabilizer UV-770, 0.3 parts of ultraviolet absorber UV-326, and 0.5 parts of catalyst U-220H.

[0066] Method (I): The above Examples 1-4 and Example 8 are all prepared according to the following process, including the following steps:

[0067] (1) Add the formulated amount of polyether polyol, solid filler, plasticizer, dispersant, light stabilizer, and ultraviolet absorber into a reaction bottle, stir evenly, and then heat the materials to dehydrate them. The temperature is raised to 100° C., and the vacuum pump is turned on to continuously evacuate to below -0.095 MPa for dehydration. The moisture content of the mixture is controlled below 0.03%.

[0068] (2) After the moisture test is passed, the mixture is cooled to below 60°C.

[0069] (3) Add a silane capping agent to the reaction bottle and react at 60° C. for 6 h. After the reaction is completed, cool the temperature to below 40° C.

[0070] (4) Add silane coupling agent, catalyst and dehydrating agent into the reaction bottle, stir for 30 minutes, and vacuum degas for 30 minutes before discharging the material to obtain a silane-modified polyether waterproof coating.

[0071] Method (ii): (1) Add the formulated amount of polyether polyol, solid filler, plasticizer, dispersant, light stabilizer and ultraviolet absorber into a reaction bottle, stir evenly and then heat the materials for dehydration. The temperature is raised to 110°C, and the vacuum pump is turned on to continuously evacuate to below -0.095MPa for dehydration. The moisture content of the mixture is controlled below 0.03%.

[0072] (2) After the moisture test is passed, the mixture is cooled to below 60°C.

[0073] (3) Add a silane capping agent to the reaction bottle and react at 70° C. for 4 h. After the reaction is completed, cool the temperature to below 40° C.

[0074] (4) Add silane coupling agent, catalyst and dehydrating agent into the reaction bottle, stir for 30 minutes, and vacuum degas for 30 minutes before discharging the material to obtain a silane-modified polyether waterproof coating.

[0075] The "less than 0.03%", "less than 60°C" and "less than 40°C" in the above methods (1) and (2) are not recorded. If the tests meet the requirements, the next step can be carried out, which does not affect the implementation of the present invention.

[0076] Method (III): (1) Add the formulated amount of silane-modified polyether MS resin and solid filler, plasticizer, dispersant, light stabilizer, and ultraviolet absorber into a reaction bottle, stir evenly, and then heat the materials for dehydration. The temperature is raised to 110°C, and the vacuum pump is turned on to continuously evacuate to below -0.095MPa for dehydration. The moisture content of the mixture is controlled below 0.05%.

[0077] (2) After the moisture test is passed, the mixture is cooled to below 60°C.

[0078] (3) Add silane coupling agent, catalyst and dehydrating agent to the reaction bottle, stir for 30 minutes, and vacuum degas for 30 minutes before discharging the material to obtain a silane-modified polyether waterproof coating.

[0079] Comparative Example 1

[0080] The raw material components of this comparative example are exactly the same as those of Example 1, except that "polyether polyol C2080B" is replaced by "polyether polyol C2080".

[0081] Comparative Example 2

[0082] The raw material components of this comparative example are exactly the same as those of Example 3, except that "polyether polyol C2180B" is replaced by "polyether polyol C2180".

[0083] Comparative Example 1 and Comparative Example 2 were prepared according to the above method (I).

[0084] Comparative Example 3

[0085] The silane-modified polyether waterproof coating is prepared according to the following raw materials in parts by weight: 30 parts of commercially available silane-modified MS resin S250 from Shanghai Dongda Chemical Co., Ltd., 30 parts of heavy calcium carbonate, 10 parts of silicon micropowder, 15 parts of DINCH, 1.0 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 0.5 parts of N-(n-butyl)-3-aminopropyltrimethoxysilane, 1.5 parts of dewatering agent KH-171, 0.5 parts of BYK-180, 0.3 parts of hindered amine light stabilizer UV-770, 0.3 parts of ultraviolet absorber UV-326, and 0.1 parts of catalyst U-220H.

[0086] The preparation method of MS resin S250 is as follows: (1) adding a formulated amount of C2080 polyether into a reaction kettle, raising the temperature to 110°C, turning on a vacuum pump to continuously evacuate to below -0.095 MPa, dehydrating, and controlling the moisture content of the mixture to below 0.03%.

[0087] (2) Add the formulated amount of antioxidant 1076, catalyst T-12 and TDI into the reactor, react at 80°C for 2 hours, and then cool to below 50°C.

[0088] (3) Add the formulated amount of isocyanate trimethoxysilane, react at 60° C. for 2 h, and then cool to below 50° C.

[0089] (4) Add the formulated amount of water absorbent KH-171, stir evenly and then discharge the material to obtain MS resin S250.

[0090] Comparative Example 3 was prepared according to the above method (iii).

[0091] The silane-modified polyether waterproof coatings prepared in the above Examples 1-10 and Comparative Examples 1-3 were tested for performance according to the sample preparation and testing methods specified in GB19250-2013, and the viscosity was tested according to the rotation method specified in GB / T10247-2008. The test results are shown in Table 1.

[0092] Table 1 Performance parameter results

[0093]

[0094]

[0095] From the preparation and test results of the above embodiments and comparative examples, it can be seen that the direct synthesis method of the present invention can simplify the preparation process of the silane-modified polyether waterproof coating from the production process of two products to the production process of one product, which greatly improves the production efficiency; the silane-modified polyether waterproof coating prepared by the self-made high molecular weight polyether blended with propylene oxide and butylene oxide has a significantly lower water absorption rate than the waterproof coating finished product prepared by the polyether containing only propylene oxide monomer, which is because the ethyl group on the polyether side chain of butylene oxide improves the hydrophobicity of the product; the silane-modified polyether using the trifunctional polyether C3180B The mechanical strength of the waterproof coating is significantly higher than that of the waterproof coating prepared using only difunctional polyether. This is because the introduction of trifunctionality increases the crosslinking density of the system when it solidifies in water, thereby improving the mechanical strength of the finished waterproof coating. The waterproof coating prepared using isocyanate dimethoxysilane as a capping agent and adding N-(n-butyl)-3-aminopropyltrimethoxysilane has a significantly higher elongation at break than waterproof coatings prepared using other formulas. This is because the dimethoxy group reduces the crosslinking density of the system, and at the same time, the flexible group of the n-butyl group plays a significant internal plasticizing role, thereby improving the elongation at break of the waterproof coating.

Claims

1. A silane-modified polyether waterproof coating, characterized in that: The invention is prepared from the following raw materials in parts by weight: 25-40 parts of polyether polyol, 40-50 parts of solid filler, 15-20 parts of plasticizer, 0.5-1.5 parts of silane end-capping agent, 0.5-2 parts of silane coupling agent, 1-2 parts of water removing agent, 0.3-1 parts of dispersant, 0.3-1 parts of light stabilizer, 0.3-1 parts of ultraviolet absorber and 0.1-1 parts of catalyst; The polyether polyol is obtained by random copolymerization of propylene oxide and butylene oxide, and has a molecular weight of 8000-20000 g / mol.

2. The silane-modified polyether waterproof coating according to claim 1, characterized in that: The functionality of the polyether polyol is 2 or 3 or a mixture of functionality 2 and functionality 3.

3. The silane-modified polyether waterproof coating according to claim 2, characterized in that: The weight ratio of the functionality 2 to the functionality 3 is 1:1 to 3:

1.

4. The silane-modified polyether waterproof coating according to claim 1, characterized in that: The solid filler is one or more combinations of silicon micropowder, talcum powder and heavy calcium carbonate.

5. The silane-modified polyether waterproof coating according to claim 1, characterized in that: The silane capping agent is one or more combinations of isocyanate propyl trimethoxy silane, isocyanate propyl dimethoxy silane and isocyanate propyl triethoxy silane.

6. The silane-modified polyether waterproof coating according to claim 1, characterized in that: The plasticizer is one of diisononyl phthalate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, diisononyl cyclohexane 1,2-dicarboxylate, and polypropylene glycol.

7. The silane-modified polyether waterproof coating according to claim 1, characterized in that: The dewatering agent is vinyl trimethoxy silane.

8. The silane-modified polyether waterproof coating according to claim 1, characterized in that: The silane coupling agent is one or two of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and N-(n-butyl)-3-aminopropyltrimethoxysilane.

9. The silane-modified polyether waterproof coating according to claim 1, characterized in that: The dispersant is a polymer-based dispersant; the light stabilizer is a hindered amine light stabilizer; the ultraviolet absorber is a benzotriazole ultraviolet absorber; and the catalyst is a chelated tin catalyst.

10. A method for improving the hydrophobicity of the silane-modified polyether waterproof coating according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) Mixing polyether polyol with solid filler, plasticizer, dispersant, light stabilizer and ultraviolet absorber, stirring evenly, heating to 100-110° C., evacuating to below -0.095 MPa, and dehydrating until the moisture content is controlled below 0.03%; (2) When the moisture content is qualified, the temperature is lowered to below 60°C; (3) adding a silane capping agent and reacting at 60-70° C. for 4-6 hours, and then cooling to below 40° C.; (4) adding a silane coupling agent, a catalyst, and a water removing agent, stirring, and vacuum degassing to obtain a silane-modified polyether waterproof coating.

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